<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>btn exercise</title>
    <link rel="stylesheet" href="my.css">
</head>

<body>
    <div class="box">
        <button class="star">Star</button>
        <button class="star sm1">Star</button>
        <button class="star sm2">Star</button>
        <button class="star sm3">Star</button>
    </div>
    <div class="box">
        <div class="dropdown">
            <button class="star sm1" type="button" id="dropdownMenu1" data-toggle="dropdown">
                Dropdown
                <span class="caret"></span>
            </button>
            <ul class="dropdown-menu">
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Action</a>
                </li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another action</a>
                </li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Something else here</a>
                </li>
                <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Separated link</a>
                </li>
            </ul>
        </div>
    </div>
</body>

</html>
